The present invention relates to a new and distinct Penstemon plant given the name ‘TNPENHPI’. Penstemon is in the family Scrophulariaceae. Penstemon ‘TNPENHPI’ originated from open-pollinated seeds of Penstemon ‘261-1’, an unnamed, unpatented, proprietary plant. It was part of a controlled breeding program to create a compact, upright, medium-small size, reblooming, and hardy series. This seedling was selected for its medium size pink flowers with white throats, flowers in dense clusters, long bloom time, good rebloom, vigor, and clean, attractive look. It is an ideal plant for a sunny border in full sun.